Management of Slow Colonic Transit Constipation in Parkinson’s Disease: Current Evidence and a Community Pharmacy Perspective

The non-motor symptoms of Parkinson's disease are often under-recognised and undertreated. Constipation is exceedingly common in Parkinson's disease, reportedly affecting up to 70% of patients. Pharmacists are ideally positioned to screen patients with Parkinson's disease for constipation and to optimise constipation management. This review will describe the evidence base for the use of different treatments in the management of constipation in patients with Parkinson's disease. PubMed, Embase and Web of Science were searched using the following search terms: "constipation" OR "gastrointestinal dysfunction" OR "slow colonic transit" OR "defecatory dysfunction" OR "slow motility" AND "treatment" OR "management" OR "therapy" AND "Parkinson* disease". The literature indicates macrogol is a safe and effective treatment for constipation in Parkinson’s disease; it should be considered a first line treatment and can be recommended by the pharmacist over-the-counter. Pharmacists can provide information regarding fibre supplementation with psyllium, which may be effective and can be initiated early. Lubiprostone appears to be a promising option, but larger and longer trials are warranted. Although many commonly employed treatments for constipation have not been evaluated for efficacy in Parkinson's disease, pharmacists can utilise available data to make evidence-based recommendations to optimise management of constipation and improve patient quality of life.